Nothing to smile about:

A man shows off his stained teeth, dyed red from years of chewing betel quids, potent parcels of areca nuts, lime and tobacco wrapped in a betel leaf. They give users a buzz when they’re chewed, but are also known to cause oral cancer.

Hundreds of millions of people chew betel quids, mostly in Asia

Research shows that chewing the parcels raises the risk of oral cancer

Betel quids are parcels of areca nuts and tobacco wrapped in a lime-coated betel leaf

In Myanmar, they’re popular with taxi drivers who use them to stay awake on the roads

Yangon, Myanmar (CNN) — Heavy users of betel quids reveal their addiction when they smile. Their teeth are stained a reddish-black, dyed from years of chewing potent parcels of areca nuts and tobacco, wrapped in a lime-coated betel leaf.